Spark-plug.



0. B. MACK. SPARK PLUG. APPucATloN FILED Nov. 22. |915.

Patented May 22, 1917.

, 7b (MZ caf/wm t may concern.'

i structed with a cylindrical central portion Patented May 22, 1917. 62,730. l

1,227,470, Specification of Letters Patent. A

Application filed November 22, 1915. Serial No.

conical portion projecting through the nut MACK, citi- 12and materially above the top of the shell;

and with a lower tapered portion projecting downwardly withinv and approximately from the bottom of the shell, and'spaced from the inner walls thereof. Thel barrel 11 also is formed with an annular shoulder or The object of this invention is toprovide @fleet l5 3 1? the uppe@` end 0f the tapered In improved Construction for park plugs lower portion, and adjacent the central cyof internal combustion engines whereby llnflfleel pOFlOIl- A coil 16, of high resisting qualities, is ofignition, and coiled around the tapered lower end portion of the porcelain barrel 11 within the chamber of the shell 10, and the lower end of said coil below the lower Be it known that l, Orio B. zen of the United States of America, and resident of Des Moines, have invented a new and Plug, of which the following is a specification.

d adjacent the point or removing carbon spark plug.

A further object of this invention is to projects Slightly introduce a resistance coil in the spark plug end 0f Slld Shell,l eIlClrcleS (preferably but through which the current is passed for once) the projecting lower end of the electrode 14, and then turns laterally and is attached to the lower end of the shell 10, 'through which it is grounded. 1 is formed in the upper portion4 of the t e purpose of heating the fuel gas in and adjacent to the spark plug and for the further purpose of removing deposits of carbon and preventing undue accumulations' thereof in the Spark plug; thereby faciliporcelain barrel 11 and has its initial endy in tating the operation of firing and increasthe ShOllldei OI' OTSe l5, leads upwardly'in ing the power of the engine. a straight line therefrom, and emerges from A further object of this invention is to the tapered Upper part 0f the barrel at a provide an improved method of mounting pOHl flbOVe th the resistance coil relative to the porcelain barrel.

A further provide a be simple and he device, the coil being mounted on the barrel from below and thev straight upper part of the coil is threaded or inserted in the channel 17, with little effort. A band 18 is mounted around the upcombination of elements hereinafter set forth, pointed out in my claim and illustrated by the accompanying drawing, in which` T e View is a central section of a spark per end portion of the barrel 11 and conplug constructed according to my invention. tacts with the ezgposed terminal of the coil In t e construction of the device as shown 16.- The band is secured by a screw 19, the numeral 10 designates the metallic shell Which also serves for the connection to said 95 of the spark plug, and 11 the insulating band of a conductor 20, which is a part of barrel, of porcelain or other suitable inathe ignitioncircuit. The lowe'rend of the terial, suitably mounted therein in a comcoil, which is thus in the ignition circuit secured by anut 12 screwed into the outer end of the shell, a washer 13 g l jump being interposed between the adjacentshoulspark to igniteA thecharge. In addition to ders of the shell and porcelain barrel. One this function the coil, which extends the enof the electrodes, 14, is mounted in and lengthwise of the porcelain barrel 11 and projects slightly below the lower end thereo to provide one of the sparking points. he porcelain barrel 11 preferably is conmon manner and to super-heat. the charge of fuel gas in the plug and cylinder head, just prior to the moment of ignition, thus greatly facilitating the ignition process. This heat, ap

fitting snugly within the interior of the plied to the fuel gas at the place of shelllO; with an upper tapered or frustoignition, 1in l heating the fuel at a i' moving any quantity of and'just prior thereto, has been found to be much more eiective than any method of place remote from the lace of ignition, such as in the manifold. his heating through the resistance coil 16 also has the effect of burning off and resoot or carbon dust which may have collected on and around the electrodes, or .in the chamber of the shell 10, and this result takes place at the time of firing so that the collection of carbon is prevented. the engine is increased by the easy and sure firing of the charge of fuel.

The coil 1G is exposed throughout the length 0i" thel chamber of the shell 10, and throughout the lower tapered length of the barrel 11, and is efective throughout its entire coiled portion in radiating heat to the surrounding parts, and to the fuel gas in the chamber and adjacent thereto, and in burning olf any incipient deposits of carbon or soot before they have accumulated to the extent of causing any loss of eiliciency in the device.

I claim as my invention A spark plug, comprisinga shell formed with a chamber, an insulated barrel tted in its central portion to said shell and tapered Thus the power and efficiency oiboth above and below said central portion,l an electrode extending longitudinally of said 4barrel and projecting at its lower end therefrom, a coil mounted around and exposed throughout the length of the tapered lower end portionoi` cling but spaced and separated from the projecting lower end of said electrode, with which said coil cooperates as a second electrode, the lower end of said second electrode being also secured to said shell, the insulated barrel being formed with a straight channel extending upwardly from the top o its lower tapered portion to an intermediate part of its upper tapered portion, said coil or second electrode being formed with a straight upper portion seated in said channel and'passing out o the upper tapered,

portion ot' said barrel, a contact member secured to said barrel in contact with the exposed upper portion o said second electrode, and a conductor secured to said contact member.

Signed by me at Des Moines, lowa, in the presence of two Witnesses.

OTT() B. MACK.

Witnesses:

p EARL M. SINCLAIR,

R. B. DENNIS.

said barrel and also encir- 

